title: Atherosclerotic plaque identification by virtual histology intravascular ultrasound in a rabbit abdominal aorta model of vulnerable plaque.
abstract: This study aimed to evaluate the utility of virtual histology intravascular ultrasound (VH-IVUS) for recognizing vulnerable plaque compared to histological pathological analysis. Four-month-old New Zealand rabbits (n = 16) were randomly divided into two groups: one fed a high-fat diet and subjected to balloon injury (experimental, n = 10) and one fed a high-fat diet alone (control, n = 6). Blood lipid profiles of overnight-fasted rabbits were measured at week 2 (beginning of study) and week 12 (end of study). At week 12, experimental group rabbits underwent IVUS under anaesthesia. Rabbits were sacrificed and a 5-cm segment of the abdominal aorta was removed. Arterial sections were subjected to pathological and immunohistochemical analyses. Serum lipid levels increased in all rabbits fed with high-fat diet, with low-density lipid cholesterol (LDL-C) levels increasing the most. Levels of six biomarkers (high sensitivity C-reactive protein, matrix metalloproteinase-3, interleukin [IL]-1, IL-10, tumour necrosis factor-α, and oxidized [ox]-LDL) showed no differences between the two groups at week 2, but were higher in the experimental group at week 12. A total of 276 atherosclerotic plaques in the experimental group were analysed. VH-IVUS had sensitivities of 87% and 92% for detection of noncalcified and calcified thin-cap fibroatheromas, respectively. VH-IVUS correctly identified 85% and 89% of noncalcified and calcified fibroatheromas, respectively. For detection of pathological intimal thickening, VH-IVUS showed a sensitivity of 79% and positive predictive value of 78%. Linear regression analysis showed a strong correlation between histology and VH-IVUS for the percent area of fibrous fibro-fatty tissue, necrotic calcified tissue, and confluent necrotic core. The intra-observer and inter-observer variability of the intimal and medial-adventitial boundaries was low. Endothelial injury followed by a high-fat diet in rabbits is a viable method for inducing atheroma, and VH-IVUS is a feasible, reproducible, and valuable means of vulnerable plaque identification in vivo.
authors.affiliation: Department of Cardiology, Union Hospital, Fujian Medical University, and Fujian Institute of Coronary Artery Disease, Fuzhou 350001, P. R. China.
authors.forename: Qing-Fei
authors.initials: QF
authors.lastname: Lin
authors.forename: Yu-Kun
authors.initials: YK
authors.lastname: Luo
authors.forename: Zi-Wen
authors.initials: ZW
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.forename: Xing-Chun
authors.initials: XC
authors.lastname: Zhen
authors.forename: Liang-Long
authors.initials: LL
authors.lastname: Chen
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D023421:Models, Animal; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D011817:Rabbits; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D015415:Biomarkers; D008055:Lipids
keywords: VH-IVUS; atherosclerosis; inflammation; intravascular ultrasound; vulnerable plaque